Originally Posted by
SebG
So what is your problem with non-euclidean geometry? I take you have a a high level understanding of mathematics and are going to blow wide open the last several centuries of map-making?
We can hypothesise that the Earth is flat, or a bowl, or whatever shape. And we can make predictions based on that hypothesis. And then we can make measurements and determine if those predictions are correct. Distances between cities corresponding to pairs of latitude lines are equal. Doesn't work if the Earth is a disc/bowl.
Astronomers have been studying the heavens for centuries and especially since the invention of the telescope have been able to observe planets and their moons and the motions of those extraterrestrial objects.
All of those observations are consistent with the Earth and the other planets orbiting the sun. We can use Newton's Laws of Gravity - to a first approximation - to make predictions about the orbits consistent with what is observed.
We have studied magnets for hundreds of years and understand how they work. This helps us understand how/why the Earth has a magnetic field and why Mars does not. Earth's magnetic field helps protect the atmosphere from being eroded by the solar wind, unlike what has happened to Mars. How's the Earth's magnetic field supposed to be generated dna dmatch what we observe if the Earth is a disc/bowl?
You've linked to 3 hours of youtube videos but you still haven't actually said anything to state your understanding.